To be even more pedantic: the original poster’s meme says skill checks don’t crit, not that nat 20s on skills are a critical success. Most skill checks in PF2e have a critical success tier. Thus jagermo was correct when they said that skill checks do crit in PF2e.
That being said, you are correct about how the whole tiering mechanic works and a nat 20 not always being a critical success. :)
Not OP, but this wiki article should help: https://en.wikipedia.org/wiki/YKK It’s the world’s largest zipper manufacturer. They officially changed their name to YKK Group so it’s not even an abbreviation anymore.